Their Unchanging Fate
by GreedLingFangirl
Summary: Diane has finally told King she loves him in the latest chapter of The Seven Deadly Sins (Chapter 216), but where will their story go from here? More specifically, where will their sex life go? In "Their Unchanging Fate" King and Diane discover exactly what comes after saying "I love you." CONTENT WARNING: EXTREME SEXUAL CONTENT (LEMON).
1. Content Warning & Disclaimer

**Howdy! Perhaps you found this story because you read my popular Soul x Maka story, "Unexpected Attraction" or perhaps you stumbled upon it while trying to find some tasteful smut. Either way, welcome!**

 **Warning: EXTREME SEXUAL CONTENT**

 **Note: This fanfic takes place after chapter 216 in the Seven Deadly Sins (Nanatsu no Taizai) manga. So, if you are not caught up, DO NOT READ if you don't want spoilers! Even if you haven't read it, chapter 216 is re-capped so it should still make sense.**

 **Disclaimer: I do not own Nanatsu no Taizai or any of the characters from the manga/anime.**

 **Final Note: If you would like to follow me on tumblr, here is a link to my blog...**

 **Please enjoy!**


	2. Deep in the Forest

"King? KING?" Diane's voice rang out.

King slowly opened his eyes.

Woof!

Oslow was sitting besides him, licking his face and his shirtless chest.

"Oh, heya Oslow...I was having a pretty great dream..."

Woof!

"What kind of a dream was it? Well, it was about Diane... and she and I...we kissed." King blushed.

"That wasn't a dream." Diane's voice came from behind King.

King turned around and looked up at Diane who was sitting behind him.

"D-DIANE!" He turned his body around to face her.

"Did I surprise you? you kinda passed out...but you look fine now!" Diane blushed.

"Umm...why did you? I mean...why did you k-kiss me? Don't get me wrong, I'm happy about it but..." King's face was red.

"It was a thanks...for keeping your promise from 200 years ago..." Diane covered her face with a pigtail. "I guess?"

"My promise...from 200 year's ago?" King's eyes got wide.

 ** _"No matter what happens, I'll always find a way to come back to you! I promise."_**

"It can't be...those memories you lost...Diane did you..."

Diane nodded. "Gowther apologized to me and returned my memories. Gowther isn't as bad as you thought..."

King hung his head. "I was so terrible to him..."

"King...I have something I have always wanted to say..." Diane blushed. "King...I always have and always will love you." She smiled. "Do...Do you still feel the same? Even now? Even after all this time?"

King was shocked.

 ** _"Will you love me forever Harlequin?"_**

 ** _"I'll love you forever and always stay by your side!"_**

 ** _"Loving me forever is enough."_**

He flew up and kissed her on the lips.

When they parted, King's face was bright red and Diane was blushing, shocked at him being so forward.

There was a long silent moment.

"Diane...I..."

Diane leaned in and kissed him again.

"Your lips are so tiny." She giggled after.

King was in a haze.

"Hey...King..." Diane said.

"Huh?" His haze was fading.

"Do you know if any of those mushrooms are around here?"

"Mushrooms?"

"You know...the ones that made me _small?_ " She was blushing again.

"Oh! I mean, they are common here in the Fairy King's forest. Why?"

"Well I..." Diane twirled her hair nervously. "I want to kiss you while I am small..."

"Oh Diane...that doesn't matter to me." King told her. "I don't care what size you are, as long as you are Diane."

"Oh King!" She smiled. "I just want to hug you! But...I can't...because I'll crush you..." She sighed.

"If it's bothering you that much...I'll find a king mushroom for you." He told her. "I'll be right back!" He flew off.

Diane let out a loud breath once he disappeared into the shrubbery.

 _Didn't he understand what she was proposing?_

King returned a moment later, with a big king mushroom.

"Alright Diane, ready?" He asked.

She nodded.

"Go ahead." King told the mushroom.

The mushroom let out a sigh then, inhaled and with a big exhale released it's shrinking pollen onto to Diane.

Diane began shrinking.

"Thanks!" King said releasing the mushroom, who waddled off with Oslow at it's heels.

King turned around to see Diane, small and very naked.

"Looks like we didn't plan for me to have any clothes!" Diane's face was red and she was covering her chest.

"D-diane!" King scrambled, looking for something to cover her with.

He noticed his rain coat laying on the forest floor.

He picked it up and handed it to her, trying his best not to look.

It was short on her, just barely covering her butt. Since King was so thin, she could only button it so high because of her massive breasts, so she had a decent amount of cleavage showing.

 _It was better than King could have ever imagined._

"Sorry about that." She said combing her hair with her fingers, as it had fallen out of the pigtails when she shrunk.

King shook his head. "We should have planned that better."

Diane wrapped her arms around King and pulled him into a tight hug. "Sometimes it's the unplanned things that work out the best."

King wrapped his arms around her too.

"I have to admit...this is nice." He said.

When they stopped hugging, turned away and stared at the ground. "Hey King..." She said in a nervous tone.

"Yes?" He asked, worried he did something to insult her.

"H-have you ever _known_ a woman?"

"Known?" King seemed confused a moment.

 _Known!?_

He realized what she meant. "NEVER!" He said way too loud and way too eagerly.

Diane's face was red.

"Oh! T-that's good to know..." She laughed nervously.

"Yeah..." King's face was red too.

She turned and faced him again, biting her lip.

"Um so..." King tried to say something, anything.

Diane leaned in and kissed him.

King melted into her lips, now the perfect size.

He placed a hand on her waist and pulled her closer to him.

Diane let out a muffled gasp and King kissed her harder.

"Diane..." He panted when their lips part. "I have never known a woman, because I have never stopped loving you!"

He kissed her.

In the blink of an eye, the two were laying on King's soft pillow kissing.

"King...I...want...you...to...touch me!" Diane said between kisses.

King's eyes got wide.

"D-diane! I c-couldnt! I shouldn't!" King was blushing like crazy.

"Yes. You should." Diane grabbed King's wrists, pulled him on top of her, and placed a hand on either breast.

King nearly passed out again.

"King! Do not pass out again!" Diane said in a breathy voice.

King gulped. "O-okay." He looked at his hands on her boobs. "Umm.." He squeezed them and Diane tossed her head back. "Like this?" He asked.

"Y-yeah!" She nodded. "T-that's good!"

King was scared his nose would bleed.

Diane lifted her head and kissed him again. She wrapped her arms around his slim body and pulled him down hard on top of her, so that their bodies were pinned together.

When their lips parted, they just stared into each other's eyes for a moment. Both of them were blushing.

"Diane..." King said looking at her body under him.

"Yes King?" She tried to use the sexiest, girly voice ever.

"Are you sure we should...I mean...I don't want to assume but you seem to want..."

Diane sighed. "I want use to be united King. So yes, I want use to make love."

 _King could barely believe his ears._

Diane took his hand and helped to guide it to the top button of his rain coat she was wearing.

"It's okay King, I want this."

King gulped and then nodded. "Okay Diane...just know that...I'm going to have no idea what I am doing." He said in a quiet voice.

"That's alright, me either." She laughed nervously.

King smiled then bit his lip and slowly began to unbutton the coat.

Button, by button, by button. His face becoming redder as he moved downward.

When all the buttons were unbuttoned, he just stopped and stared at her naked body peeking through the open coat.

"What's wrong?" Diane asked.

"I have...I have always wanted this. You have no idea..." King sounded so amazed.

Diane's face turned red and she smiled.

In an instant, she pushed him off of her and rolled so that she was on top of him.

She leaned over and kissed him quickly, then slipped off the coat completely.

There she was, sitting on top of him naked.

 _It was all too much for King._

"Ooo!" She giggled, rocking her hips. "I feel that." She was referring to his ever-growing bulge in his pants that she was currently sitting on.

She slid down, so that she was sitting on his legs and began working at removing his pants.

 _This was really happening. King expected to wake up any moment and realize it had all been a dream._

Once Diane loosened his belt, she slid his pants off.

There they were, both naked.

Diane stared at his erection, then she rolled over so that she was laying next to him.

"It um...might be easier this first time if you are on top." She said nervously.

"Oh, yeah." King nodded. He climbed on top of her.

They both stared at each other.

"Are you sure Diane?" King said after a moment.

"Uh huh." Diane nodded.

King kissed her.

"I love you Diane." He told her.

He touched her face with his smooth hand.

"I love you too King." Diane's eyes were full of tears.

King let out a sigh and looked down at her body. "Okay." He said.

He slowly began to move his shaft towards her moist opening. He got to the edge of it, and looked her in the eyes.

She reached for his hand and he held hers.

Then with his other hand, he directed himself into her.

Diane let out a gasp as he slowly pushed in.

King moved his hand from his shaft to her breast and she bit her lip and squeezed his hand tighter as he pushed and pushed until he was almost completely inside her.

"Does it hurt?" He asked her.

"A...a little." Diane winced.

King slowly began to pull back out again.

"Wait King I can..."

Before she could finish her sentence, King pushed back inside. This time deeper.

Diane let out a squeal.

He kept doing this until he was able to get a rhythm going.

King let out a moan.

"Diane this is amazing! You are amazing!" He went faster.

"Y-you feel s-so good!" Diane whined. She then squeezed his hand tighter and closed her eyes.

"King! I might...I might..." She yelped and King felt her insides get tighter around his shaft. Her whole body began to shake.

King kissed her and let her ride out her orgasm, then he picked up where he left off. Diane practically drooling after climaxing for the first time.

After a bit, King moved his hand from her breast to her face and Diane kissed him.

King moaned, he felt himself on edge. "Diane I'm going to...I mean...should I..."

"DO IT KING! JUST DO IT!" Diane screamed.

King moaned and thrust harder. He grabbed both of her hands and held them tight.

Seconds later he burst into a fit of moans and released all of his warm fluids inside of her. Diane moaned too, feeling them gush inside her.

Then King collapsed on top of her, resting his head on her breasts. Both of them were panting like crazy.


End file.
